Push-pin and christmas-tree fasteners are well known within the art. These fasteners are designed for secure fit and difficult removal while at the same time allowing for easy insertion.
A particular challenge in using these types of fasteners, especially in the automotive field, lies in providing a fastener that will afford the most secure attachment in combination with the simplest insertion process and fewest additional parts or insertion steps. Often, improper insertion direction results in loose fit and the risk of separation. Additionally, there is a need for fasteners that can prevent a fastened part from pivoting about the fastener, without the need for additional fasteners or attachments.
Other problems include the difficulty in maintaining the fastener centered within an aperture so that it may have less of a tendency to loosen within the aperture or slip out of the aperture completely. A fastener with a basic rounded shank runs the risk of separation with any aperture that is not circular and of similar diameter.
The prior art includes many christmas-tree type fasteners. U.S. Pat. No. 3,810,279 discloses a drive fastener having a head, polygonal shaft and axially staggered wings along the shaft. U.S. Pat. No. 4,728,238 discloses another drive fastener having a head, polygonal shank and wings arranged along the shank. U.S. Pat. No. 5,468,108 discloses a spiral tree-fastener having a head and a flattened shank, wherein the shank contains a plurality of flexible wings arranged at an oblique angle with respect to the fastener axis.
One problem that arises with the use of some existing fastener structures is that their size and shape do not allow for ideal fit and security within an aperture. This unfortunately results in slipping and disengagement of the fasteners. Further, most push-pin fasteners are not capable of providing secure fastening to a multi-layer substrate, nor do they have the capability of fastening substrates with a wide variety of thicknesses with one standard fastener.
As another problem, many push-pin fasteners provide no means to ensure that the fastener is inserted in the ideal position to ensure maximum secure fit. As such, fasteners that are inserted upside-down, sideways or at any other imperfect position, are again subject to rotation, slippage, disengagement, or at the very least, abnormally difficult insertion. Those fasteners that are circular in nature and thus not subject to improper insertion direction often fail to fit securely within any non-circular aperture, resulting in slippage and disengagement.
A further issue with many fasteners is that multiple fasteners or additional attachments are often required to prevent slippage, disengagement, or a fastened part from twisting about a fastener. This results in increased parts, labor, and maintenance.
The present invention addresses one or more of the above problems, and represents an improvement to existing fasteners for use within vehicles. Accordingly, a fastening system for a vehicle component is disclosed. The fastener typically includes a head or cap and a shank with at least two side walls. At least one of the side walls is typically lined with wing structures. The fastening system further includes a complimentary shaped aperture within a substrate as part of a vehicle component.